This invention relates to exercise devices for rotating a human user in oscillation and into inverted posture. This type of device is known and is described in U.S. Pat. No. 3,707,285 (Martin), U.S. Pat. No. 3,716,231 (Martin) and U.S. Pat. No. 4,232,662 (Barber). Ankle holding devices are also known and are described in U.S. Pat. No. 3,380,447 (Martin) and my co-pending application, Ser. Nos. 203,707 and 203,336.
The currently known configurations of tilt beds are subject to problems related to the size (and hence weight) of the user. When currently known tilt beds are fully inverted with a user, the foot supporting means passes across the vertical plane through the pivot bearings where the center of gravity of the combined user and tilt bed structure are far enough past the pivot bearings to securely hold the user in inverted posture. The foot supporting means on such known devices are adjustably mounted on a straight rail wherein a larger user is supported when inverted from a point further past the pivot bearing plane than a smaller person. As a result of this inherent geometry a taller (and hence heavier) person tends to lock more solidly into the inverted orientation, and a shorter (and hence lighter) person has difficulty staying inverted. This is a serious shortcoming, since there is some tendency towards panic if the tall user has difficulty in getting out of the inverted posture, and the device is obviously useless to a small person who cannot stay inverted.